Spring mechanism for toilet seat and toilet seat

ABSTRACT

A spring mechanism for returning a seat plate to a desired angular position relative to a toilet seat includes a rotatable pivot shaft mounted on the toilet seat and interactable with the seat plate so that the shaft is rotated whenever the seat plate is rotated over its angular travel, a first spring interconnecting the toilet seat and the pivot shaft for biasing the seat plate towards the desired angular position, and a pawl engageable with the rotatable pivot shaft as the pivot shaft is urged by the first spring to rotate in a first direction for moving the seat plate to the desired angular position. The engagement temporarily holds the rotation of the seat plate in the first direction for a period of time until the pivot shaft disengages the pawl due to the spring force exerted thereon by the first spring. In an exemplary toilet seat embodiment according to an aspect of the invention, when the seat plate returns to the desired angular position, the seat plate can be sterilized automatically.

BACKGROUND

1. Field of the Invention

The present application relates to toilet seats and spring mechanisms for raising a seat plate of a toilet seat to a desired angular position.

2. Background of the Invention

It may be desirable to maintain the seat plate of a toilet seat in a vertical or upright position when it is not in use, especially in public toilets. Spring biased seats for returning the seat plate to the desired position are known, and various improvements have been made. For example, U.S. Pat. No. 4,402,092, filed by Larry L. Smallwood on Oct. 2, 1981, discloses the uses of a slipping clutch to slow the angular rotation of the seat plate to its spring-biased position.

However, in design of the '092 patent, as soon as the user leaves the seat plate of the toilet seat, the seat plate starts rising up. This may not be convenient or comfortable to the user.

Furthermore, it may be desirable to sterilize the seat plate regularly.

OBJECT OF THE INVENTION

Therefore, it is an object of the present invention to provide an improved spring mechanism for returning a seat plate, which may hold the seat plate for a while as the seat plate starts returning to a desired position, or at least provide the public with a useful choice.

It is another object of the present invention to provide an improved toilet seat, whose seat plate can be held for a while as it starts returning to a desired position, or at least provide the public with a useful choice. Preferably, the toilet seat can be sterilized automatically.

SUMMARY OF THE INVENTION

According to an aspect of the present invention, a spring mechanism for returning a seat plate to a desired angular position relative to a toilet seat includes a rotatable pivot shaft mounted on the toilet seat and interactable with the seat plate so that the shaft is rotated whenever the seat plate is rotated over its angular travel, a first spring interconnecting the toilet seat and the pivot shaft for biasing the seat plate towards the desired angular position, and a pawl engageable with the rotatable pivot shaft as the pivot shaft is urged by the first spring to rotate in a first direction for moving the seat plate to the desired angular position. The engagement temporarily holds the rotation of the seat plate in the first direction for a period of time until the pivot shaft disengages the pawl due to the spring force exerted thereon by the first spring.

According to a second aspect of the present invention, a toilet seat includes

-   -   a seat plate; and     -   a spring mechanism for returning the seat plate to a desired         angular position relative to the toilet seat, including:         -   a rotatable pivot shaft mounted on the toilet seat and             interactable with the seat plate so that the shaft is             rotated whenever the seat plate is rotated over Its angular             travel;         -   a first spring interconnecting the toilet seat and the pivot             shaft for biasing the seat plate towards the desired angular             position; and         -   a pawl engageable with the rotatable pivot shaft as the             pivot shaft is urged by the first spring to rotate in a             first direction for moving the seat plate to the desired             angular position,         -   wherein said engagement temporarily stops the rotation of             the seat plate in the first direction for a period of time             until the pivot shaft disengages the pawl due to the spring             force exerted thereon by the first spring.

Preferably, the toilet seat includes a mechanism for automatically sterilizing the seat plate when the seat plate returns to the desired angular position.

Other aspects and advantages of the invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, which description illustrates by way of example the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an elevation view illustrating a toilet seat according to an exemplary embodiment of the present invention and a water tank, the cover plate being in a horizontal position and the seat plate being in a substantially vertical position;

FIG. 2 is a top plan view of the toilet seat of FIG. 1, the cover plate and seat plate being in a closed position;

FIG. 3 is a side view of the toilet seat of FIG. 1, illustrating part of a spring mechanism;

FIG. 4 is an enlarged partial side view illustrating the cover plate, the seat plate and part of the spring mechanism;

FIG. 5 is a perspective view illustrating part of the spring mechanism;

FIG. 6 a is a top plan view illustrating part of the spring mechanism;

FIG. 6 b is a side view illustrating the exterior of the spring mechanism;

FIG. 7 a is a cross-section view along line E-E′ of the spring mechanism of FIG. 6 b;

FIG. 7 b is another cross-section view along line F-F′ of the spring mechanism of FIG. 6 b;

FIG. 8 a is an enlarged side view of a pawl of and a retention cam of the spring mechanism of FIG. 7 b;

FIG. 8 b is an exploded view of pawl and the cam of FIG. 8 a;

FIG. 9 is a simplified elevation view of the toilet seat of FIG. 1, illustrating the rotation range of the seat plate between the opened and closed positions;

FIGS. 10 a-c illustrate interactions between the pawl and cam of FIGS. 8 a and 8 b when the seat plate is rotated from the substantially vertical position to the horizontal position; and

FIGS. 11 a-c illustrate interactions between the pawl and cam of FIGS. 8 a and 8 b when the seat plate rotates from the horizontal position to the substantially vertical position.

DETAILED DESCRIPTION

FIG. 1 illustrates an exemplary toilet seat embodiment 100 of the present invention and a water tank 101 generally in use with the toilet seat 100. The toilet seat 100 generally stands on the floor 103 with the water tank 101 aligned with the wall 105. The toilet seat generally has a toilet bowl 107, a seat plate 109 and a cover plate 111 both atop the toilet bowl 107 as could be understood by the person in the art. Both the seat plate 109 and the cover plate 111 are individually pivotably mounted to the toilet bowl 107, and thereby both can independently rotate between a generally horizontal position 115 and a substantially vertical position 117.

FIGS. 2-4 illustrate both the seat plate 109 and the cover plate 111 in the horizontal position 115. As shown in FIGS. 2-4, suction rubber dampers 301 are attached to a bottom of the seat plate 109 and in contact with the toilet bowl 107 when the seat plate 109 rests atop the toilet bowl 107 in the horizontal position for temporarily preventing the seat plate rising up. In addition, as shown in FIGS. 3 and 4, part 405 of bottom of the cover plate 111 facing the seat plate 109 is modeled in a same configuration as the seat plate 109 for catering the same. Replaceable self-adhesive sterilization paper towels are attached to said part 405 of the bottom of the cover plate and can be in contact with the seat plate 109 for automatic sterilization of the seat plate 109.

Furthermore, the cover plate 111 is pivotably mounted to a primary shaft 401 through a cover plate hanging arm 201; the seat plate 109 is secured to the primary shaft 401 through a seat plate hanging arm 203 and a pair of screws 205 so that rotation of the seat plate 109 between the vertical and horizontal positions causes rotations of the primary shaft 401 as well. The primary shaft 401 is pivotably or rotatably mounted to a pair of brackets (not shown) projecting from the toilet bowl 107 as could be understood in the art. A retention box 207 is also mounted on the primary shaft for housing a spring mechanism 501 (see FIG. 5).

As shown in FIGS. 5-8, the spring mechanism 501 is provided in the retention box 207 for automatically raising the seat plate 109 from the horizontal position to the vertical position. The primary shaft 401 passes through a pair of walls 503 of the retention box, and as the seat plate 109 is rotated to the horizontal position for use, rotation of the primary shaft 401 is transmitted to a secondary shaft 505 through a pair of gears 507, 509 mounted to the primary and second shafts 401, 505 respectively. A torsion spring 511, with one end mounted onto one of the walls 503 and the other end mounted to the secondary shaft, is biased as the seat plate 109 is rotated towards the horizontal position, and the spring force of the torsion spring biases, through the primary and second shafts and the gears, the seat plate 109 towards the vertical position. Therefore, the seat plate will be automatically lifted to the vertical position if there are no constraints. Furthermore, a pair of retention pawls 601 is provided in the retention box to interact with a pair of corresponding retention cams 603 mounted to the secondary shaft 509 for temporarily holding the secondary shaft for a period of time. Through such mechanism, as a user leaves the seat plate, the seat plate is held in its horizontal position for a period of time before it is driven to the vertical position by the torsion spring.

Each pawl 601 is pivotably mounted to a bracket 807 in the retention box through a screw passing though a hole 805 thereon and a corresponding nut 803. One end 701 of the pawl 601, relatively distanced from the pivot 703, is connected to an end of a tension spring 705, the other end of which is mounted to the bottom 707 of the retention box 207. The other end 709 of the pawl 601, relatively closer to the pivot 703, provides a relatively steep retention surface 809 on one side for engaging a mating engaging surface 811 of a projection 813 provided on the engaging cam 603. The other side of end 709 provides a curved surface 815, which can be in smooth contact with the engaging cam.

Operation of the spring mechanism 501 is described as follows. When the toile seat is in use, the cover plate is generally in its vertical position, and the seat plate is rotated to its horizontal position. During such rotation, the torsion spring on the secondary shaft is biased. As the user leaves the seat plate and no restraints are exerted on the seat plate, due to the spring force of the torsion spring, the secondary shaft is rotated in a counter-clockwise direction as indicated by arrow S′ in FIG. 8 a. Rotation of the secondary shaft in direction S′ drives the seat plate to rise up to its vertical position. In the beginning of the rising up of the seat plate, as the engaging surface 811 comes into engagement with the retention surface 809 as shown in FIG. 8 a, due to the spring force of the tension spring 705, the secondary shaft 505 is held in this position temporarily for a period of time until the engaging surface disengages the retention surface. In other words, rising-up of the seat plate is temporarily stopped.

The torsion spring, the tension spring and the lever system provided by the pawl are configured such that the spring force of the torsion spring will overcome the spring force of the tension spring so that the retention cam further pushes down end 709 of the pawl 601 until they disengage each other. Thereafter, without the constraints by the pawl 601, the torsion spring further rotates the secondary shaft 505 in the S′ direction and consequently lifts up the seat plate.

With reference to FIGS. 9, 10 a-c and 11 a-c, interactions between the pawl and the cam during various stages when the seat plate is rotated in the clockwise and counterclockwise directions are described as follows.

In the exemplary embodiment, the ratio of the numbers of the teeth of gears 507, 509, which are mounted to the primary and second shafts respectively, is set to be 3:1 so that as the primary shaft is rotated by 100 degrees, the second shaft is rotated by 300 degrees. % ice versa.

As shown in FIG. 9, in the exemplary embodiment, the seat plate is rotated by approximately 100 degrees as it is rotated between the horizontal position and the substantially vertical position. Therefore, the second shaft will be rotated by 300 degrees during such rotations.

FIG. 10 a illustrates the angular positions of the cam and the pawl when the seat plate is in its substantially vertical position and is in contact with the sterilization paper towel for sterilization. A virtual horizontal line “A,” passing through the center 1001 of the second shaft 505, is used for reference. The pawl extends at least substantially horizontally. A virtual line 1003, passing through the center 1001 and end 709 of the pawl, extends at approximately 45-60 degrees relative to reference line “A.” Virtual line 1005, passing through the engaging surface 811 and the center 1001, extends at approximately 30-45 degrees relative to reference line “A.” Clockwise, lines 1005 and 1003 extend at approximately 290 degrees.

During rotation of the seat plate from its substantially vertical position to the horizontal position, when the second shaft has been rotated clockwise as shown by arrow 1007 by approximately 290 degrees, the projection 813 comes in contact with curved surface 815 of the pawl and thereby pushes the pawl to rotate counter-clockwise. Spring 705 is compressed.

As the seat plate is rotated further to its horizontal position, the engaging surface 811 passes the pawl to a position slightly above the pawl when the second shaft has been rotated by 300 degrees. Due to a clearance between the pawl and the cam (not shown) and the spring force of the spring 705, the pawl returns to its balanced position, in which the pawl extends substantially horizontally.

FIGS. 11 a-c illustrate the automatic rotation of the seat plate from Its horizontal position towards its substantially vertical position. In the beginning, as shown in FIG. 11 a, as the second shaft has been rotated counter-clockwise indicated by arrow 1101 by approximately 10 degrees, i.e., when the seat plate is rotated upwards by approximately 3 degrees from its horizontal position, the engaging surface 811 comes into contact with end 7-9 of the pawl. Such engagement holds the second shaft in this position temporarily for a period of time.

Due to the spring force of the torsion spring 511, the engaging surface 811 pushes down the pawl as shown In FIG. 11 b until they disengages each other. Afterwards, as shown in FIG. 11 c, the second shaft further rotates counter-clockwise to its balanced position of FIG. 10 a. During such rotation, as shown in FIG. 11 c, the pawl 601 may be in contact with the external surface of the cam 604 and thereby exerts a friction force thereon. The spring mechanism is configured to minimize the effect by such friction force so that the seat plate is rotated to its vertical position smoothly.

Furthermore, when the seat plate is lifted to its vertical position, it becomes in contact with the sterilization paper towel so that automatic sterilization is achieved. 

1. A spring mechanism for returning a seat plate to a desired angular position relative to a toilet seat, comprising: a rotatable pivot shaft mounted on the toilet seat and interactable with the seat plate so that the shaft is rotated whenever the seat plate is rotated over its angular travel; a first spring interconnecting the toilet seat and the pivot shaft for biasing the seat plate towards the desired angular position; and a pawl engageable with the rotatable pivot shaft as the pivot shaft is urged by the first spring to rotate in a first direction for moving the seat plate to the desired angular position, wherein said engagement temporarily holds the rotation of the seat plate in the first direction for a period of time until the pivot shaft disengages the pawl due to the spring force exerted thereon by the first spring.
 2. The spring mechanism of claim 1, further comprising an engaging tooth mounted on the pivot shaft for engaging the pawl.
 3. The spring mechanism of claim 1, wherein the pivot shaft includes a profile with an engaging surface for engaging the pawl.
 4. The spring mechanism of claim 3, wherein the profile is designed to provide a clearance, which allows the pawl to move to a position after it has disengaged the engaging surface so that the pawl will not be in engagement with the pivot shaft during subsequent rotation of the pivot shaft in the first direction.
 5. The spring mechanism of claim 3, wherein the pivot shaft includes a retention hook mounted thereon for providing said profile with the engaging surface.
 6. The spring mechanism of claim 1, further comprising a second spring for biasing the pawl towards the pivot shaft.
 7. The spring mechanism of claim 6, wherein the pawl is pivotable mounted to the toilet seat with one end connected to the second spring and the other end to engage the pivot shaft.
 8. The spring mechanism of claim 7, wherein the second spring is a tension spring.
 9. The spring mechanism of claim 1, further comprising an idler shaft to which the toilet seat is secured so that the shaft is rotated whenever the toilet seat is rotated over its angular travel; a transmission mechanism between the idler shaft and the pivot shaft for correlating rotations of the idler shaft and the pivot shaft.
 10. The spring mechanism of claim 6, wherein the first spring is a torsion spring mounted to the pivot shaft.
 11. A toilet seat, comprising a seat plate; and a spring mechanism for returning the seat plate to a desired angular position relative to the toilet seat, Including: a rotatable pivot shaft mounted on the toilet seat and interactable with the seat plate so that the shaft is rotated whenever the seat plate is rotated over its angular travel; a first spring interconnecting the toilet seat and the pivot shaft for biasing the seat plate towards the desired angular position: and a pawl engageable with the rotatable pivot shaft as the pivot shaft is urged by the first spring to rotate in a first direction for moving the seat plate to the desired angular position, wherein said engagement temporarily stops the rotation of the seat plate in the first direction for a period of time until the pivot shaft disengages the pawl due to the spring force exerted thereon by the first spring.
 12. The toilet seat of claim 11, wherein the pivot shaft includes a profile with an engaging surface for engaging the pawl.
 13. The toilet seat of claim 12, wherein the profile is designed to provide a clearance, which allows the pawl to move to a position after it has disengaged the engaging surface so that the pawl will not be in engagement with the pivot shaft during subsequent rotation of the pivot shaft in the first direction.
 14. The toilet seat of claim 11, further comprising a second spring for biasing the pawl towards the pivot shaft.
 15. The toilet seat of claim 14, wherein the pawl is pivotable mounted to the toilet seat with one end connected to the second spring and the other end to engage the pivot shaft.
 16. The toilet seat of claim 11, further comprising an idler shaft to which the toilet seat is secured so that the shaft is rotated whenever the toilet seat is rotated over its angular travel; a transmission mechanism between the idler shaft and the pivot shaft for correlating rotations of the idler shaft and the pivot shaft.
 17. The toilet seat of claim 11, further comprising at least one suction rubber damper mounted to a bottom of the seat plate for temporarily holding the rotation of the seat plate in the first direction.
 18. The toilet seat of claim 11, further comprising means for automatically sterilizing the seat plate when the seat plate returns to the desired angular position.
 19. The toilet seat of claim 11, further comprising a cover plate generally atop the seat plate; and a sterilized paper towel attached to a bottom of the cover plate for sterilizing the seat plate when it is in engagement with the seat plate.
 20. The toilet seat of claim 19, wherein the sterilized paper towel is self-adhesive and is shaped to receive the seat plate surface.
 21. The toilet seat of claim 20, wherein the cover plate is modeled in accordance with the configuration of the seat plate surface. 